The paper suggesting that bees benefit from tobacco and other nectars containing secondary toxic metabolites hasn't raised any comment.  I thought I'd stir the pot a bit by reminding folks that nicotine stimulates acetylcholine (ACh) receptors, just like neonicotinoids do.  The difference is that nicotine has a half-life of a couple hours, disengaging from the receptors....whereas neonicotinoids lock onto the insect's ACh receptors, holding them in the "open" position, for a very long time.


 The experiment exposed bumblebees artificially inoculated with a gut protozoan to eight different secondary metabolites found in nectars:  including alkaloids (anabasine, caffeine and nicotine), iridoid glycosides (aucubin and catalpol), phenolics (gallic acid), terpenoids (thymol) and cyanogenic glycosides.


Their results were that four of these compounds reduced the protozoan load very significantly:  anabasine (81% reduction), catalpol (61%), nicotine (62%) and thymol (67%).  All eight compounds had a negative effect on the protozoan.


So...how is it that bees taking nicotine could be helped in ridding themselves of parasites, as that article suggests?  Nicotine is toxic to bees.  But if low doses of nicotine *can* be helpful to bees, then since neonics work just the same way, why do the research papers out there say neonics are either "fairly safe" or "toxic" but never "beneficial" to honeybees?


Maybe bees respond to nicotine like people do.  We know that is true of caffeine...that was discussed here last year.  Could it be that whereas nicotine can be beneficial to bees at a low dose, and toxic at a high dose, neonics are just too powerful to be anything but toxic?   Many papers now show that neonics have nothing but a negative effect on honeybee colonies, from outright acute toxicity (rare these days) to more subtle disturbances such as cognitive problems, enhanced viral load, and exacerbation of other chronic colony ailments leading to poor overall colony performance.


Reminds me of all those endless drug commercials on US television....example:  "Ask your doctor about X.  X is wonderful to treat your pesky restless leg syndrome, but X can produce severe side effects such as (blah blah blah) and death."  Pharmaceuticals in overdrive...I believe that's the neonic story.

Christina

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